Root Bark Of Dictamnus Dasycarpus Research Articles

Structure and activity of new degraded products of limonoid from root bark of Dictamnus dasycarpus, and insights from broadened NMR spectra into self-aggregation of hydroxy acids

Five degraded products of limonoid, including two previously undescribed compounds (1, 3) and one pair of new natural products (4i, 4ii), were isolated from the root bark of Dictamnus dasycarpus Turcz. Their structures were elucidated by extensively spectroscopic methods (NMR, MS, ECD, etc), as well as quantum chemical calculations. The broadening NMR lines, along with the relaxation time and DOSY experiment revealed the self-aggregation of 1 in chloroform through H-bond between –COOH and –OH, which provided additional evidence to distinguish acid and ester/lactone in structure elucidation. Compounds 1–3 attenuated oleic acid-induced lipid accumulation in HepG2 cells significantly, with inhibition rates of 19.8%, 23.6%, and 13.5% at 10 μM, much stronger than fenofibrate, affording a novel scaffold for drug discovery against fatty liver disease.

Natural compound fraxinellone ameliorates intestinal fibrosis in mice via direct intervention of HSP47-collagen interaction in the epithelium.

Intestinal fibrosis is a common complication of inflammatory bowel disease. There is still a lack of effective drugs for the prevention or treatment of intestinal fibrosis. Heat shock protein 47 (HSP47) plays a key role in the development of intestinal fibrosis. In this study we investigated the therapeutic potential and underlying mechanisms of fraxinellone, a degraded limonoid isolated from the root bark of Dictamnus dasycarpus, in the treatment of intestinal fibrosis. Intestinal fibrosis was induced in mice by dextran sodium sulfate (DSS) treatment. DDS-treated mice were administered fraxinellone (7.5, 15, 30 mg·kg-1·d-1, i.g.) for 45 days. We showed that fraxinellone administration dose-dependently alleviated DSS-induced intestinal impairments, and reduced the production of intestinal fibrosis biomarkers such as α-smooth muscle actin (SMA), collagen I, hydroxyproline, fibronectin and laminin, and cytokines such as TGF-β, TNF-α and IL-β. We then established in vitro intestinal fibrosis cell models in SW480 and HT-29 cells, and demonstrated that treatment with fraxinellone (3, 10, 30 μM) significantly relieved TGF-β-induced fibrosis responses by inhibiting the TGF-β/Smad2/3 signaling pathway. Molecular docking suggested that the fraxinellone might disrupt the interaction between HSP47 and collagen, which was confirmed by coimmunoprecipitation experiments. SPR analysis showed that fraxinellone had a high affinity for HSP47 with a Kd value of 3.542 × 10-5 M. This study provides a new example of HSP47-collagen intervention by a natural compound and has important implications for the clinical treatment of inflammation-induced issue fibrosis.

Chemical constituents and pharmacological effects of Dictamni Cortex: a review

Dictamni Cortex, the dried root bark of Dictamnus dasycarpus, has many chemical constituents, such as alkaloids, limonoids, flavonoids, sesquiterpenoids, glycosides, and steroids.It has the effects of anti-inflammation, anti-fungi, anti-arteriosclerosis, stopping bleeding, anti-cancer, neuroprotection, and antioxidation.The chemical constituents of Dictamni Cortex are the important material basis for its medicinal effects.This paper reviewed the chemical constituents and pharmacological activities of Dictamni Cortex and analyzed the research trend and present research progress on this medicinal, with a view to its further development and utilization.

Dictamnine, a novel c-Met inhibitor, suppresses the proliferation of lung cancer cells by downregulating the PI3K/AKT/mTOR and MAPK signaling pathways

Dictamnine (Dic), a naturally occurring small-molecule furoquinoline alkaloid isolated from the root bark of Dictamnus dasycarpus Turcz., is reported to display anticancer properties. However, little is known about the direct target proteins and anticancer mechanisms of Dic. In the current study, Dic was found to suppress the growth of lung cancer cells in vitro and in vivo, and to attenuate the activation of PI3K/AKT/mTOR and mitogen-activated protein kinase (MAPK) signaling pathways by inhibiting the phosphorylation and activation of receptor tyrosine kinase c-Met. Moreover, the binding of Dic to c-Met was confirmed by using cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) assay. Among all cancer cell lines tested, Dic inhibited the proliferation of c-Met-dependent EBC-1 cells with the greatest potency (IC50 = 2.811 μM). Notably, Dic was shown to synergistically improve the chemo-sensitivity of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-resistant lung cancer cells to gefitinib and osimertinib. These results suggest that Dic is a c-Met inhibitor that can serve as a potential therapeutic agent in the treatment of lung cancer, especially against EGFR TKI-resistant and c-Met-dependent lung cancer.

Identification and characterization of quinoline alkaloids from the root bark of Dictamnus dasycarpus and their metabolites in rat plasma, urine and feces by UPLC/Qtrap-MS and UPLC/Q-TOF-MS

Quinoline alkaloids are the main bioactive and potentially toxic constituents in the root bark of Dictamnus dasycarpus Turcz. (BXP), a widely used traditional Chinese medicine for the treatment of skin inflammation, eczema and rubella. However, the comprehensive analysis of the chemical components and metabolites of quinoline alkaloids remain unclear. In this study, an integrated strategy by combining UPLC/Q-TOF-MS and UPLC/Qtrap-MS was established to comprehensively profile the quinoline alkaloids from BXP and their metabolites in rat plasma, urine and feces. Q-TOF-MS (MSE mode), Qtrap-MS (EMS, MIM, pMRM and NL mode) were performed for acquiring more precursor ions and clearer precursor product ions. A step-by-step manner based on the diagnostic fragment ions (DFIs), in-house database, ClogP value and dipole moment (μ) was proposed to overcome the complexities due to the similar fragmentation behaviors of the quinoline alkaloids. As a result, a total of 73 quinoline alkaloids were unambiguously or tentatively identified. Among them, 4 furoquinolines, 10 dihydrofuroquinolines, 2 pyranoquinolinones, 4 dihydropyranoquinolinones and 9 quinol-2-ones were characterized in BXP for the first time. Moreover, a total of 98 BXP-related constituents (including 57 prototypes and 41 metabolites) were detected in rat plasma, urine and feces. The metabolic pathways included phase I reactions (O-demethylation, hydroxylation and 2,3-olefinic epoxidation) and phase II reactions (conjugation with glucuronide, sulfate and N-acetylcysteine). In conclusion, the integrated strategy with the proposed stepwise manner is suitable for rapid identifying and characterizing more extensive quinoline alkaloids of BXP in vitro and in vivo. Moreover, the results will be helpful for revealing the pharmacological effective substances or toxic substances of BXP and provide a solid basis for further research.

Rapid identification, isolation, and evaluation on anti-neuroinflammatory activity of limonoids derivatives from the root bark of Dictamnus dasycarpus

A total of 49 limonoids derivatives were rapidly identified by UNIFI software and three new limonoids derivatives, named dasycarinone (1, DAS), isodictamdiol C (2) and dasycarinone A (3), along with nineteen known compounds, were isolated from the root bark of Dictamnus dasycarpus, named as “Baixianpi” in Chinese. Their structures were elucidated on the basis of spectroscopic data (UV, IR, HR-ESI-MS, NMR, CD spectra and OR). All the compounds were tested for anti-inflammatory activities by suppressing the nitric oxide (NO) production in lipopolysaccharide (LPS) induced BV-2 cells. DAS exhibited a strong anti-inflammatory activity with IC50 value of 1.8 μM. Nuclear Factor kappa B (NF-κB) luciferase assay and enzyme-linked immune sorbent assay indicated that DAS can suppress the release of inflammatory cytokines such as Tumor Necrosis Factor α (TNF-α), interleukin 6 (IL-6) via inactivating NF-κB signaling pathways. Moreover, we found that anti-inflammatory activities of obacunone-class are better than those of limonin-class by analyzing structure-activity relationship. Our results suggested that obacunone derivatives play an important role on anti-inflammation of Baixianpi. As a representative among them, DAS showed a strong anti-inflammatory activity via suppressing NF-κB signaling pathways.

Anti-inflammatory quinoline alkaloids from the root bark of Dictamnus dasycarpus

Six undescribed quinoline alkaloids, named dasycarines A–E, and 18 known ones were isolated from the root bark of Dictamnus dasycarpus. All the structures were elucidated on the basis of comprehensive analysis of UV, IR, NMR, and HRMS spectroscopic data, and the absolute configurations were assigned via comparison of the calculated and experimental ECD data. (+)-Dasycarine A (1a) and (−)-Dasycarine A (1b) are a pair of enantiomers of dimeric furoquinoline alkaloid, which are the first dimeric via [2 + 2] cycloaddition of furan. The structure and absolute configuration of (−)-dasycarine A was determined via X-ray crystallography. Additionally, all the isolated compounds were tested for their inhibitory effects on NO production stimulated by LPS in BV-2 microglial cells. Three compounds showed strong inhibition with IC50 values below 5.0 μM; nine compounds exhibited inhibition with IC50 values in the range of 7.8–28.4 μM. Furthermore, we demonstrated that preskimmianine suppressed the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and nuclear factor kappa B (NF-κB) in LPS-induced BV-2 microglial cells.

Three new compounds from Dictamnus dasycarpus and their anti-inflammatory activities

Three new compounds (1–3), named dasycarine G (1), dasycarether (2), and dasycarester (3), along with seven known compounds (4–10) obtained from the genus Dictamnus for the first time, were isolated from the root bark of Dictamnus dasycarpus. Their structures were elucidated on the basis of spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR, and CD). In the in vitro assay, compounds 1, 5, 6, 9, and 10 exhibited NO inhibitory effects of LPS-induced BV-2 cells with IC50 values in the range of 10.4 μM to 27.2 μM.

Chemical constituents from root barks of Dictamnus dasycarpus and their cytotoxic activities

Nineteen compounds, including kihadanin D (1), obacunone (2), kihadanin A (3), kihadanin B (4), kihadanin C (5), limonin (6), evodol (7), fraxinellone (8), furo[2,3-b]quinolin-4-ol (9), preskimmianine (10), ifflaiamine (11), dictamnol (12), naringenin (13), diosmetin (14), wogonin (15), scopoletin (16), cleomiscosin A (17), apocynin (18), and methyl pyroglutamate (19), were isolated from the methanol extract of the root barks of Dictamnus dasycarpus by using various column chromatographies. Their chemical structures were extensively determined on basis of UV, IR, NMR, MS, and CD spectroscopic data analyses. Among them, 1 is a new limonoid, 9 was isolated from plant kingdom for the first time, 11, 13-14 and 17-19 were obtained from the genus Dictamnnus for the first time. Cytotoxicities of compounds 1-18 were tested, and the results indicated that 1 exhibited cytotoxicities against three human cancer cell lines MDA-MB-231, A549 and HT29 with IC₅₈ values of 16.22, 21.72 and 31.06 μmol·L⁻¹, respectively.

Disentangling the Complexity of a Hexa-Herbal Chinese Medicine Used for Inflammatory Skin Conditions-Predicting the Active Components by Combining LC-MS-Based Metabolite Profiles and in vitro Pharmacology.

Objectives: The purpose of this study is to investigate the anti-inflammatory activity of a hexa-herbal Chinese formula (HHCF) using spontaneously immortalized human epidermal keratinocytes (HaCaT) and to predict the active components by correlating the LC-MS-based metabolite profiles of the HHCF and its 12 varied formulae with their anti-inflammatory activity using partial least-squares regression analysis.Methods: The HHCF comprises the rootstock of Scutellaria baicalensis, Rheum tanguticum, Sophora flavescens, the root bark of Dictamnus dasycarpus, the bark of Phellodendron chinense, and the fruit of Kochia scoparia in equal proportions. Its 12 varied formulae were developed by uniform design with varied proportions of the component botanical drugs. The decoctions of the HHCF and its 12 varied formulae were profiled using liquid chromatography (LC) combined with triple quadrupole mass spectrometry (MS) and their effects on tumor necrosis factor (TNF)-α -plus-interferon (IFN)-γ-induced C-C motif chemokine ligand 17 (CCL17) production in HaCaT were investigated. Partial least-squares regression analysis was conducted to assess the relationship between the LC-MS-based metabolite profiles of the decoctions to anti-CCL17 production in HaCaT.Results: Compounds with potential to promote anti-CCL17 production in HaCaT were identified (e.g., berberine, pyrogallol and catechin dimers) as a result of the developed model and their potential to act as anti-inflammatory agents were also supported by relevant literature.Conclusion: This promising approach should assist in the screening process of active components from complex Chinese herbal preparations and will better inform the necessary pharmacological experiments to take forward.

Mass spectrometry guided strategy based on feature fragment ions for guided-separation on quinoline alkaloids from root barks of Dictamnus dasycarpus

The root bark of Dictamnus dasycarpus is one of common traditional Chinese medicines (TCMs). Quinoline alkaloids are one of the main active substances in this TCM and possess many biological activities including anti-titumor, anti-inflammation, anti-bacteria, anti-oxidation, and anti-platelet aggregation activities. In this study, eight quinoline alkaloids 1-8 were firstly separated from the root barks of D. dasycarpus. It was difficult to isolate more quinoline alkaloids from the remaining fraction 8 in D. dasycarpus by this conventional chemical separation, so the target analysis method combined LC-MS guided-separation of quinoline alkaloids from fraction 8 was established. MS/MS fragmentation patterns of eight quinoline alkaloids reference standard compounds 1-8 were studied by ultra-performance liquid chromatography-electrospary ionization-mass spectrometry (UPLC-ESI-MS/MS). Based on the feature fragment ion m/z 200, the parent ion scan mode was established for the target analysis of quinoline alkaloids in fraction 8. Finally, 8-methoxyflindersine (9) and N-metilatanina (10) were discovered and isolated quickly from fraction 8 guided by LC-MS, and their structures were identified by NMR and MS. Among them, compound 10 was isolated from the genus Dictamnus for the first time. These results indicated that this method is not only quick and sensitive for analyzing the quinoline alkaloids, but also to effectively guided-separate this kind of alkaloids in the root barks of D. dasycarpus.

Eudesmane-Type Sesquiterpene Glycosides from Dictamnus dasycarpus Turcz.

Eudesmane-type sesquiterpenes have been reported to exhibit varieties of biological activities. During the process of investigating this kind of natural product from the root bark of Dictamnus dasycarpus Turcz., 13 eudesmane-type sesquiterpene glycosides including six new isolates, named as dictameudesmnosides A1 (1), A2 (2), B (3), C (4), D (5), and E (6), together with seven known ones (7–13), were obtained. Herein, their structures were determined by the analysis of physical data, spectroscopic analysis, and chemical methods. The existence of α-configuration glucose units in their structures (1–5, 8) is not very common in natural glycosidic components. Meanwhile, compounds 3–5, 7, and 9–13 displayed TG accumulation inhibitory effects on HepG2 cells.

A Hexa-Herbal TCM Decoction Used to Treat Skin Inflammation: An LC-MS-Based Phytochemical Analysis.

In order to understand the chemical relationship between a traditional hexa-herbal Chinese medicine formula and botanical drugs it is derived from, an analytical platform comprising liquid chromatography coupled with triple quadrupole mass spectrometry and data mining was developed to separate and identify key chemical components. The hexa-herbal formula comprises the rootstock of Scutellaria baicalensis, Rheum tanguticum, Sophora flavescens, the root bark of Dictamnus dasycarpus, the bark of Phellodendron chinense, and the fruit of Kochia scoparia. Seventy-three compounds including alkaloids, anthraquinone derivatives, coumarins, coumarins derivatives, flavonoids, flavone glycosides, naphthalene derivatives, phenylbutanone glucopyranoside, phenolic acids, pterocarpans, stilbenes, stilbenes derivatives, and tannins were putatively identified based on mass measurement and characteristic fragment ions. Among the botanical drugs of the hexa-herbal Chinese medicine formula, the rootstock of R.tanguticum and S. flavescens, bark of P. chinense, and rootstock of S. baicalensis contributed to the majority of the extracted metabolites of the formula decoction. The developed method appeared to be a versatile tool for monitoring chemical constituents in extracts of a traditional Chinese medicine formula in a relatively comprehensive and systematic manner, and helped to understand the importance of the individual botanical drugs within a formulation.

Glabretal-type triterpenoid from the root bark of Dictamnus dasycarpus ameliorates collagen-induced arthritis by inhibiting Erk-dependent lymphocyte proliferation

Ethnopharmacological relevanceThe root bark of Dictamnus dasycarpus Turcz. (Rutaceae) has been used as a traditional herbal medicine to treat various inflammatory diseases in East Asia. We have showed previously that a glabretal type triterpenoid (dictabretol A) from D. dasycarpus root bark has immunosuppressive activity. Aim of the studyThis study was conducted to define the molecular mechanism of how dictabretol A inhibits lymphocyte proliferation and to evaluate the therapeutic efficacy of dictabretol A in an animal model of rheumatoid arthritis. Materials and methodsVarious murine immune cells (T cells, B cells, and macrophages) and splenocytes were used to study the anti-proliferative effect of dictabretol A in vitro. A collagen-induced arthritis model was also used to examine the therapeutic effect of dictabretol A in vivo. ResultsDictabretol A specifically inhibited lymphocyte proliferation by blocking the cell cycle transition from the G1 to the S phase. This effect was achieved by blocking Erk1/2, nuclear factor kappa B, and the C-myc axis of cell cycle progression. Further dictabretol A treatment alleviated the severity of collagen-induced arthritis. ConclusionOur results reveal the molecular mechanism for the anti-lymphoproliferative effect of dictabretol A and show the therapeutic efficacy of dictabretol A for rheumatoid arthritis.

Antiproliferative glabretal-type triterpenoids from the root bark of Dictamnus dasycarpus

Four new glabretal-type triterpenoids, dictabretols A–D (1–4), were isolated by activity-guided fractionation from the root bark of Dictamnus dasycarpus T. (Rutaceae) using an in vitro antiproliferative assay on T cells using splenocytes. The structures of these compounds were determined by spectroscopic methods, including 2D NMR experiments. Compounds were evaluated for their immunosuppressive activity on T cells and demonstrated inhibition of proliferation of activated T cells, up to IC50 of 1.5μM.

Effects of Dictamnus dasycarpus Turcz., root bark on ICAM-1 expression and chemokine productions in vivo and vitro study

Ethnopharmacological relevanceThe root bark of Dictamnus dasycarpus Turcz., family Rutaceae is a well known anti-inflammatory agent for skin diseases such as eczema, pruritus and urticaria in Eastern countries. Materials and methodsWe investigated the effects of methanol extract of Dictamnus dasycarpus root bark (MEDD) on Intercellular Adhesion Molecule-1 (ICAM-1) expression, epidermal hyperplasia and immune cell infiltration in 1-fluoro-2,4-dinitrofluorobenzene (DNFB)-induced contact dermatitis (CD) mice. We also investigated its effects on the expression of ICAM-1, binding capacity to THP-1 cells, cytokine and chemokine production, and phosphorylation of NF-κB in human keratinocytes (HaCaT cells). ResultsTopical application of MEDD effectively inhibited ICAM-1 expression and epidermal hyperplasia in inflamed tissues. MEDD treatment also inhibited immune cell infiltration induced by DNFB. In addition, treatment with MEDD reduced surface expression and total amount of ICAM-1in HaCaT cells and effectively lowered the capacity to bind to THP-1 cells. MEDD also lowered the levels of IL-6, IL-8, monokine induced by gamma interferon (MIG), monocyte chemotactic protein-1 (MCP-1) and regulated on activation, normal T cell expressed and secreted (RANTES). Finally, MEDD treatment prevented activation of the NF-κB pathway induced by TNF-α in HaCaT cells. ConclusionsThese data indicate that root bark of Dictamnus dasycarpus has the potential for treatment of inflammatory skin diseases as a complementary or alternative medicine to corticosteroids. In addition, they suggest that the anti-inflammatory effects of Dictamnus dasycarpus on CD are involved in the regulation of ICAM-1 expression and cytokine and chemokine secretion through down-regulation of the NF-κB signaling pathway in keratinocytes.

Two new apotirucallane-type isomeric triterpenoids from the root bark of Dictamnus dasycarpus with their anti-proliferative activity

Two new apotirucallane-type isomeric triterpenoids, named as dictamnin A (1) and dictamnin B (2), with six limonoids, obacunone (3), limonin (4), rutaevin (5), 7α-obacunyl acetate (6), fraxinellone (7), fraxinellonone (8), were isolated from the root bark of Dictamnus dasycarpus Turcz. (Rutaceae). Their structures were well determined by means of IR, MS, 1D and 2D NMR techniques. Both new apotirucallane-type isomeric triterpenoids displayed good antiproliferative effects on lung cancer cells A549 and resulted in a clear increase of the percentage of cells in G1 phase and a decrease in the percentage of cells in S and G2/M phases in comparison with control cells.

Erratum to: Neuroprotective effects of constituents of the root bark of Dictamnus dasycarpus in mouse hippocampal cells

Erratum to: Neuroprotective effects of constituents of the root bark of Dictamnus dasycarpus in mouse hippocampal cells

Dictamins A–C, three unprecedented apotirucallane-type trinortriterpenoids from Dictamnus dasycarpus

Dictamins A–C, the first known examples of apotirucallane-type trinortriterpenoids, were isolated from the root bark of Dictamnus dasycarpus . Their structures and relative configurations were elucidated on the basis of extensive NMR and single-crystal X-ray diffraction analyses. Such compounds might be the key C 5 side chain intermediates for an alternative degradation process from protolimonoids (C 8 side chain) to limonoids (C 4 side chain), bridging an oxidative cleavage biogenetic pathway between these two classes of structurally diverse triterpenoids.

Two new compounds from Dictamnus dasycarpus

Two new compounds, one new pyrrolidine alkaloid and one new eudesmane-type sesquiterpene derivative, named, respectively, as dictamnaindiol and dictamnadiol, were isolated from the EtOAc soluble fraction of the ethanolic extract from the root barks of Dictamnus dasycarpus. Their structures were elucidated as (3α,4β)-3-(6-ethoxy-6-(4-hydroxyphenyl)methyl)-4-(4-hydroxyphenyl)-1-methyl-pyrrolidin-2-one (1) and (1R, 4S, 7S, 10R)-1,11-dihydroxyl-4,14-epoxy-5(6)-eudesmene (2) on the basis of their spectral and chemical analysis.